1. Technical Field
The invention relates to a method and to a device for processing and separating an imbricate formation of flexible, flat and flexible objects, in particular, printed products.
2. Prior Art
From the state of the art there are known various feeders and devices, specifically in order to isolate printed products or to grasp these individually and to transfer these products for further transport to a conveyor. The disadvantages of the state of the art are due to the counter-running movement pattern, the large inertia and friction forces and the abrupt directional change. With the machines used today the operations are not flowing, but have a static component. This means that a printed product to be processed is brought completely to a standstill in order to be then accelerated abruptly in another direction. This has a negative effect, particularly at high processing speeds.
From CH 324210 by Müller, entitled Anlegemasehine für die Pavier industrie, and published on 15 Sep. 1957, there is known, for example, a feeder machine for the paper industry. This serves for feeding folded printed sheets onto saddles of a feeder transport belt of a binding machine. The device is based on a drum which is arranged between a stack of folded printed sheets supported on an oblique plane and a transport belt with saddles. The printed sheets are arranged standing on their folds in the feed region. The drum which is arranged essentially tangentially to the frontmost printed sheet on its periphery, comprises a gripper by way of which the respective frontmost printed sheet of the ply is gripped and pulled off at the cut-edge side. Pulling-off the next printed sheet is only possible if the previous sheet has been completely removed from the stack. Each printed sheet is deflected and borne on the drum, and thrown off onto a saddle of the feed transport belt. With this device, in each case only one printed sheet is processed per operating cycle; this results in a limitation on the processing speed due to the basic operating principle. So that the printed sheet may be grasped, it is furthermore necessary for the drum of the gripper to carry out a counter-directed movement. With fast-running machines, this leads to high inertia forces. Due to the functioning principle on which it is based, this device is not suitable for processing large volumes, and furthermore, the separation at the cut-edge side is burdened with problems.
DE 2531262 by Güither Schick, entitled Hochleistungsanleger für Loseblatt oder gefalzte Lagen aus Papier oder ähntich biegsamen Werkstoffen and published on 25 Jan. 1977, shows a feeder for sheets or folded layers of paper or similarly flexible materials. Printed sheets, in the form of an imbricate flow (leading edge at the top) are moved along an oblique plane by way of a conveyor belt. The printed sheets on a further oblique plane are piled up into an obliquely set position and brought to a standstill. The respective lowermost printed sheet of the oblique ply is grasped by way of a wheel equipped with grippers and deflected by way of a deflection roller. By way of this, the printed sheets are pulled from the obliquely set position. In contrast to the device known from Hans Müller in CH 324210, the printed sheets are not pulled off individually, but are pulled of in the form of a continuous, imbricate flow. Due to the large deflection during the step of pulling-off, the printed sheets are excessively loaded. For isolating the printed sheets, a suggestion has been made to arrange an acceleration path after this.
EP 1055620 by Keller et al., and published on 29 Nov. 2000, of the same applicant shows a device for accommodating and for the further transport of flat, printed products. A multitude of grippers with associated suction members are attached along a revolving wheel. The printed sheets to be processed are arranged on a stack from which they are lifted by way of the suction members and brought into the active region of the grippers. The printed sheets are gripped by the grippers and subsequently deposited in the form of an imbricate flow and conveyed away by a conveyor. This device permits the gripping of printed sheets within very short distances, wherein the suction heads and products are aligned with one another.
EP 1086914 entitled DEVICE FOR TRANSPORTING FLEXIBLE AND FLAT PRODUCTS, by Egon Hänsch, published on 28 Mar. 2001, shows a device for the transport of flat products from a stationary stack positioned in a receiving location to a dispensing location. The device comprises a separating member, as well as a support element and a holding member which are arranged running around a shaft. The products are gripped individually, separated and transferred to a device that serves as an exit conveyance. With this device the products are also mechanically loaded.
WO 00/46135 entitled DEVICE FOR UNSTACKING A PILE OF FLAT OBJECTS, ESPECIALLY PRINTING PRODUCTS, by Willy Leu. published on 10 Aug. 2000, shows a device for reducing a stack of flat objects, in particular, printer's products. By way of a lift, the respective uppermost printed sheet is lifted from a stack and brought into the active region of a conveyor belt which serves for leading away the printed sheets in the form of an imbricate flow. The device is designed such that it is adaptable to the height of the stack. Although it is simplified in comparison to the state of the art, the device requires a control.
EP 0863099 entitled DEVICE FOR SEPARATING PILED PRINTED PRODUCTS, by Alex Keller, published on 9 Sep. 1998, shows a device for isolating stacked printer's products. The printed sheets to be processed are inserted below a stack by way of conveyor. From this stack the respective uppermost printed product is gasped by a gripper and led away individually. So that the printed sheets may be gasped, they are individually lifted by way of a lifting mechanism and brought into the active region of the gripper.
EP 0755886 entitled DEVICE FOR FEEDING PRINTED PRODUCTS TO A FURTHER WORK STATION, by Alex Keller, published on 29 Jan. 1997, shows a device for feeding folded printers' products to a location for further processing. Printed sheets supplied in an imbricate flow are led to a stacking location by way of a conveyor, where they are inserted below an intermediate stack. By way of a lifting member (e.g., a suction member) moved along a circumferential path, the respective uppermost printer's product is lifted at the fold's edge and brought into the active region of a conveyance. The conveyance uses a segmented roller and a circumferential belt which serves for pressing the printed products onto the segmented roller. The printed sheets are lifted one after the other and brought into the active region of the conveyance by which they are grasped and led away in the form of an imbricate flow.
DE 19627830 by Jürg Eberie, published on 6 Feb. 1997, shows a device for feeding printed products to a conveyance. A suction member arranged on the inside of a rotor engages through a recess when grasping a printers' product and draws a corner region into the interior of the rotor. The printers' product is then engaged at the bottom by a rotor arm and lifted farther in order to bring it into the active region of a conveyor. The printed products are conveyed away, either individually or in the form of an imbricate flow, by way of grippers.
EP 0675061 entitled “DEVICE FOR CONTINUOUSLY FEEDING FLAT ARTICLES TO A DELIVERY POINT”, by Honegger et al., published on the 10th of Dec. 1997, shows a device for an uninterrupted supply of flat products to a dispensing location. The printers' products are led to the dispensing location by way of an endless conveyor belt. At the dispensing location the conveyor belt, at least in regions, is guided around a deflection roller and extends around the deflection wheel in an undershooting manner. The conveyor belt driven by a stepper motor and a deflection wheel form a conveying gap for the products to be processed which are arranged in an imbricate formation. The respective uppermost product of a partial stack is grasped by way of a suction head and lifted.
As may be deduced from the above-described documents, the devices known from the state of the art for separating printers' products have a relatively complicated construction, wherein the complexity is partly due to the control. Depending on the mentioned principles, the processing speed is furthermore limited so that the printed products are not excessively loaded and the processing steps are effected in a reliable manner. Most known devices are based on the fact that printed products that require further processing need to be brought completely to a standstill so that they may be grasped by a gripper or equivalent device. Inasmuch as fluent processing is desired, in the state of the art expensive designs, special controls, are required in order to be able to separate the printed products with high accuracy. A further disadvantage of conventional designs for continuous processing, i.e., if the printed product is not to be brought completely to a standstill, lies in the fact that (a limited) buffering with but short-term malfunctioning may be accommodated, in indeed if at all, by complicated sensors with control and regulation installations. For this reason as well as others, most devices envisage a “static” intermediate stack from which the printed products (that have previously been braked to a standstill or almost to a standstill) are accelerated, pulled off and isolated.